Distribution Planning

The fundamental philosophies of distribution planning were beautifully articulated by M. V. Engel et al. in the following statements:

“Distribution planning is the process of study and analysis through which an electric utility assures itself that it will economically and reliably meet its future power delivery obligations. Such planning is important to the future economic health of the utility, providing a means to minimize the cost of delivering the utility's product to its customers. Good distribution planning provides lower capacity requirements, more reliable service and better overall company planning, all contributing to lower rates. Modern distribution planning methods also improve the use of company resources, provide better projections of future expenses and help satisfy regulatory and licensing requirements for new construction.

A good distribution plan identifies the types, sizes, locations, routes, interconnections and timing for future sub transmission lines, substations, feeders and related power delivery equipment. It minimizes future power delivery costs by balancing losses costs against capital capacity construction costs, minimizing their sum. “ [1]

“The foundation of the planning process is the distribution load forecast, which defines how much power the future distribution system will be expected to deliver, and to where. Forecasting for distribution planning involves projecting the locations of future customers and load, in order to identify problem areas in advance and support substation siting and feeder routing studies. “ [1]

The perspective provided by Engel et al. is shared by Root 3 engineers who believe that one of the most critical components of distribution planning and the starting place for planning is the collection of load data, analysis of load data and load forecasting. It is this focus which lead to the development of the ATILDA methodology. The ATILDA methodology was developed to provide a more analytic approach to load analysis, growth estimation, and forecasting. 

If the planner does not start with good load data and/or is not able to create forecasts with high accuracy, then there is a requirement to plan and OVER design the electric system to accommodate uncertainty of the load requirements of the system. 

If the planner starts with good load data and is able to create forecasts with high accuracy, then there is an opportunity to plan and design the electric system to the load requirements of the system. 

Designing/planning using good data and good forecasts (using ATILDA) results in:

1. Less money spent on capital equipment that is not required yet or at all

2. Less time spent by the planners comming up with solutions to problems that do not exist yet or at all

3. Less time spent by design engineers designing system improvements that are not required yet or at all

4. Less time spent by construction crews building system improvements that are not required yet or at all

5. Less time spent by operations to accommodate construction efforts related to projects that are not required yet or at all

6. Less explanation and justification required for the State Utilities Commission 

[1] M. V. Engel et al., editors, Tutorial on Distribution Planning, IEEE Course Text EHO 361-6-PWR, IEEE, Hoes Lane, NJ, 1992.